A closed loop generation and/or infusion system comprising a radionuclide generator, an activity detector, a controller, a dose calibrator, a pump, eluant source and an automated elution system controlled by software and hardware for generation and infusion of a radionuclide for administering a dose of generated radionuclide into a subject for diagnosing a peripheral arterial disease in a subject suffering from or suspected of suffering from peripheral arterial disease and/or metabolic disease by performing quantitative assessment of blood flow in lower extremities or limbs of the subject:
- wherein the quantitative assessment is performed by analyzing one or more images and providing a severity score;
- and wherein the analysis of the one or more images is performed by using an automated system.